Genotypic and Phenotypic Characteristics of Vancomycin-resistant Enterococcus Isolated from Clinical Specimens of Patients in Shahrekord

Background and Enterococci are important agents of endocarditis and urinary tract infections. They acquire resistance against antimicrobial agents which causes difficulty in their treatment. This study aimed to determine the antimicrobial susceptibility of strains resistant to vancomycin and identification of resistance genes vanA and vanB Enterococcus strains isolated from teaching hospitals in 2014. Hundred and fifty isolates of Enterococcus were isolated from hospitals and the genus and species composition were identified using different biochemical methods. Antibiogram tests were also conducted. The minimum inhibitory concentration was conducted applying broth micro dilution. Finally the strains containing vanA and VanB genes were identified. The antibiogram test showed 10 strains with VanA and VanB phenotype. All strains were resistant to ciprofloxacin. VanA and VanB genes were detected in all 10 isolates of vanA phenotype and two strains of vanB phenotype. VanA and VanB genes were proliferated by PCR in two strains of the10 strains that were VanA phenotype. Among Enterococcus species E. faecium and E. faecalis isolates were detected in teaching hospitals. The highest rate of resistance was to erythromycin and tetracycline and the lowest resistance rate was to vancomycin.